Question

When sending an email from C# with body being large is resulting in failure in sending email

Mailbox unavailable.

The email is working fine with a smaller body. I am using html body to true property..

Thanks,
Zafar

Code:

using (MailMessage _mailMsg = new MailMessage())
                    {
                        _mailMsg.From = new MailAddress(ConfigurationManager.AppSettings["mailFrom"].ToString());
                        _mailMsg.Body = mail.Body;
                        _mailMsg.Subject = mail.Subject;
                        _mailMsg.IsBodyHtml = true;

                        foreach (string strEmailIds in mailTo)
                        {
                            if (strEmailIds != null && strEmailIds != string.Empty && strEmailIds != "")
                            {
                                if (!_mailMsg.To.Contains(new MailAddress(strEmailIds)))
                                    _mailMsg.To.Add(new MailAddress(strEmailIds));
                            }
                        }
                        //_mailMsg.CC.Add(ConfigurationManager.AppSettings["mailCC"].ToString());
                        using (SmtpClient _client = new SmtpClient(ConfigurationManager.AppSettings["Host"].ToString()))
                        {

                            if (_mailMsg.To.Count > 0)
                            {

                                _client.Send(_mailMsg);
                            }
                            else
                            {
                                _mailMsg.Subject = "No emails associated with the portfolio: " + account + " Original Email:" + mail.Subject;
                                _mailMsg.To.Add(new MailAddress(ConfigurationManager.AppSettings["mailSuppotTeam"].ToString()));
                                _client.Send(_mailMsg);
                            }

Answer 1

The issue was with sending email to cross domain email id and was resulting in the Generic exception
“Mailbox unavailable.” May be this is one of the reason behind the above exception.